1. Field of the Invention
The present invention relates to an image output method of registering converted character patterns in a font cache memory, and, in response to the reception of a code corresponding to one of said character patterns, forming a visible memory by the character pattern registered in said font cache memory, and an apparatus therefor.
2. Related Background Art
There are recently commercialized various apparatus, such as laser beam printer, adopting a scalable font such as outline font.
Said outline font is featured by the easiness in working on the desired characters, but necessitates a longer time required for generating the character dot pattern. For this reason, the character pattern which has been used at least once in the past is registered in the font cache memory, together with the information on "character set identification (for example gothic style)", "character code" and "size (height and width of character)", and, when the same character is instructed, the character pattern is read from the font cache memory and developed into dot form. Thus the processing time of the apparatus is shortened by effecting the generation of the character pattern only once for the character of same code and same style.
It will be understood that, in the conventional method mentioned above, the character pattern is generated at the entry of a character code and thus generated character pattern is registered in the font cache memory. For this reason, the character pattern registered in the font cache memory can be utilized for the second and subsequent entries of the character code, but the effect of process time reduction cannot be attained for the character code entered for the first time, as the generation of the character pattern has to be executed anew.
Also in the conventional recording apparatus as explained above, the outline font is usually composed of a train of contour coordinates representing the form of the character, but there exist various methods for forming such coordinates. For this reason, in the apparatus there is provided, according to the method of constituting the outline font, exclusive means for generating character dot patterns (font scaler or rasterizer). Consequently, if there are employed multiple outline fonts constituted by plural methods, there have to be provided font scalers respectively corresponding to such methods.
Also the character dot patterns generated by such different font scalers may be mutually different, even for a same style, a same size and a same character code, because of differences in the constituting method of the font, in the designing of character shape or in the process in the font scalers.
For this reason, a character dot pattern, which has been used at least once in the past, is registered in the font cache memory together with the information of font scaler, character set identification, character code and size, and is read from the font cache memory area and is developed into a character dot pattern in response to the entry of the same character code. In this manner the process time of the apparatus for pattern generation can be reduced by effecting the generation only once in each font scaler for a same character dot pattern.
In such conventional recording apparatus with plural font scalers, since the font cache memory only registers the information of the character set identification, character code and size, there has been a drawback that the character dot patterns prepared by different font scalers cannot be identified.
Also since the character pattern is generated only at the end of the character code, in a mode of use of the recording apparatus in which the content of the output character information is frequently changed, the advantage of the font cache memory cannot be expected for the character code entered for the first time, and there is required a considerable time before the character is printed.